[DCCP]: Simplify skb_set_owner_w semantics

  
While we're at it let's reorganise the set_owner_w calls a little so that:
  
1) dccp_transmit_skb sets the owner for all packets except data packets.
2) Add dccp_skb_entail to set owner for packets queued for retransmission.
3) Make dccp_transmit_skb static.
  
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

2 files changed, 14 insertions, 10 deletions

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 5871c027f9dc..f97b85d55ad8 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -118,7 +118,6 @@ DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
 #define DCCP_ADD_STATS_USER(field, val) \
                         SNMP_ADD_STATS_USER(dccp_statistics, field, val)
 
-extern int  dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
 extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
 
 extern int dccp_send_response(struct sock *sk);
diff --git a/net/dccp/output.c b/net/dccp/output.c
index d59f86f7ceab..c25b0423887a 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -12,6 +12,7 @@
 
 #include <linux/config.h>
 #include <linux/dccp.h>
+#include <linux/kernel.h>
 #include <linux/skbuff.h>
 
 #include <net/sock.h>
@@ -25,13 +26,20 @@ static inline void dccp_event_ack_sent(struct sock *sk)
         inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 }
 
+static inline void dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
+{
+        skb_set_owner_w(skb, sk);
+        WARN_ON(sk->sk_send_head);
+        sk->sk_send_head = skb;
+}
+
 /*
  * All SKB's seen here are completely headerless. It is our
  * job to build the DCCP header, and pass the packet down to
  * IP so it can do the same plus pass the packet off to the
  * device.
  */
-int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
+static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 {
         if (likely(skb != NULL)) {
                 const struct inet_sock *inet = inet_sk(sk);
@@ -63,6 +71,9 @@ int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
                 skb->h.raw = skb_push(skb, dccp_header_size);
                 dh = dccp_hdr(skb);
 
+                /*
+                 * Only data packets should come through with skb->sk set.
+                 */
                 if (!skb->sk)
                         skb_set_owner_w(skb, sk);
 
@@ -393,10 +404,8 @@ int dccp_connect(struct sock *sk)
 
         DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST;
         skb->csum = 0;
-        skb_set_owner_w(skb, sk);
 
-        BUG_TRAP(sk->sk_send_head == NULL);
-        sk->sk_send_head = skb;
+        dccp_skb_entail(sk, skb);
         dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL));
         DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS);
 
@@ -425,7 +434,6 @@ void dccp_send_ack(struct sock *sk)
                 skb_reserve(skb, MAX_DCCP_HEADER);
                 skb->csum = 0;
                 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK;
-                skb_set_owner_w(skb, sk);
                 dccp_transmit_skb(sk, skb);
         }
 }
@@ -482,7 +490,6 @@ void dccp_send_sync(struct sock *sk, const u64 seq,
         DCCP_SKB_CB(skb)->dccpd_type = pkt_type;
         DCCP_SKB_CB(skb)->dccpd_seq = seq;
 
-        skb_set_owner_w(skb, sk);
         dccp_transmit_skb(sk, skb);
 }
 
@@ -507,10 +514,8 @@ void dccp_send_close(struct sock *sk, const int active)
         DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ?
                                         DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ;
 
-        skb_set_owner_w(skb, sk);
         if (active) {
-                BUG_TRAP(sk->sk_send_head == NULL);
-                sk->sk_send_head = skb;
+                dccp_skb_entail(sk, skb);
                 dccp_transmit_skb(sk, skb_clone(skb, prio));
         } else
                 dccp_transmit_skb(sk, skb);